Cesium之实体Entity先来看 Entity 的各个属性属性解释 id 唯一标志，如果没设置，值就为一个默认给

先来看 Entity 的各个属性

属性	解释
id	唯一标志，如果没设置，值就为一个默认给定的GUID
name	名称，可以不唯一
availability	可用性
show	可见性
description	描述
position	位置
orientation	方向
viewFrom	查看此对象的初始偏移量
parent	父节点
properties	与此实体关联的任意属性
Graphics	相关的形状

标签 label

文字标注,可以设置样式，文字内容，字体，偏移等等

label : {
    text : 'Citizens Bank Park',
    font : '14pt monospace',
    style: Cesium.LabelStyle.FILL_AND_OUTLINE,
    outlineWidth : 2,
    verticalOrigin : Cesium.VerticalOrigin.BOTTOM,
    pixelOffset : new Cesium.Cartesian2(0, -9)
}

模型 model

常见的模型有glTF 和glb

model : {
    uri : '../../SampleData/models/CesiumGround/Cesium_Ground.gltf'
}

广告牌 billboard

一个最简单的广告牌一般就是图片，和显示大小

billboard : {
  image : 'http://localhost:81/images/2015/02-02/Philadelphia_Phillies.png',
  width : 64,
  height : 64
}

增

创建一个实体参考：

//方法一
var entity = new Entity({
    id : 'uniqueId'
});
viewer.entities.add(entity);

//方法一 简写
viewer.entities.add({
    id : 'uniqueId'
});

//方法二
var entity = viewer.entities.getOrCreateEntity('uniqueId');

查

查找实体的方法：

var entity = viewer.entities.getById('uniqueId');

改

修改Entity的属性值：

var entity = viewer.entities.getById("测试点001");
if (entity) {
  entity.point.color=Cesium.Color.GREEN.withAlpha(0.8)
}

修改Entity的位置：

var entity = viewer.entities.getById("测试点001");
if (entity) {
  entity.position.setValue(p)
}

删

移除实体的方法：

//方法一，先查后删
var entity = viewer.entities.getById('uniqueId');
viewer.entities.remove(entity) 
//方法二，直接删除
viewer.entities.removeById('uniqueId')
//方法三，删除所有
viewer.entities.removeAll()

contains

if (viewer.entities.contains(entity)) {
    console.log("实体已存在");
} else {
    console.log("实体未创建");
}

实体集变化

function onChanged(collection, added, removed, changed){
  var msg = 'Added ids';
  for(var i = 0; i < added.length; i++) {
    msg += '\n' + added[i].id;
  }
  console.log(msg);
}
viewer.entities.collectionChanged.addEventListener(onChanged);

描述信息官网示例

只需要修改entity 的description 属性就可以达到目的

var viewer = new Cesium.Viewer('cesiumContainer');

var wyoming = viewer.entities.add({
  name : 'Wyoming',
  polygon : {
    hierarchy : Cesium.Cartesian3.fromDegreesArray([
                              -109.080842,45.002073,
                              -105.91517,45.002073,
                              -104.058488,44.996596,
                              -104.053011,43.002989,
                              -104.053011,41.003906,
                              -105.728954,40.998429,
                              -107.919731,41.003906,
                              -109.04798,40.998429,
                              -111.047063,40.998429,
                              -111.047063,42.000709,
                              -111.047063,44.476286,
                              -111.05254,45.002073]),
    height : 0,
    material : Cesium.Color.RED.withAlpha(0.5),
    outline : true,
    outlineColor : Cesium.Color.BLACK
  },
  description:'divID'//方法一
});

viewer.zoomTo(wyoming);

//方法二
wyoming.description = '\
<img\
  width="50%"\
  style="float:left; margin: 0 1em 1em 0;"\
  src="//cesiumjs.org/images/2015/02-02/Flag_of_Wyoming.svg"/>\
<p>\
  Wyoming is a state in the mountain region of the Western \
  United States.\
</p>\
<p>\
  Wyoming is the 10th most extensive, but the least populous \
  and the second least densely populated of the 50 United \
  States. The western two thirds of the state is covered mostly \
  with the mountain ranges and rangelands in the foothills of \
  the eastern Rocky Mountains, while the eastern third of the \
  state is high elevation prairie known as the High Plains. \
  Cheyenne is the capital and the most populous city in Wyoming, \
  with a population estimate of 62,448 in 2013.\
</p>\
<p>\
  Source: \
  <a style="color: WHITE"\
    target="_blank"\
    href="http://en.wikipedia.org/wiki/Wyoming">Wikpedia</a>\
</p>';

选中

scene 提供了两个方法来获取选中对象，参数都是两个(viewer, windowPosition)
– pickEntity 获取最顶层的实体 – drillPickEntities 获取当前位置的所有实体的集合(List)

Cesium之实体Entity